The use of organopolysiloxanes as microcapsule shell wall materials, and processes for their preparation are known. A common feature of all the processes heretofore described, is that the shell walls are formed from already prepared organopolysiloxanes.
The use of solid, thermoplastic organosiloxane polymers for shell walls is described, for example, in U.S. Pat. No. 5,254,656. The organosiloxane polymers must be dissolved in suitable solvents, the solution added under exactly controlled conditions to the material to be encapsulated, and the solvent removed again by a complicated procedure.
The use of liquid organosiloxane polymers for shell walls is described, for example, in U.S. Pat. No. 4,370,160. The liquid organosiloxane polymers must then be converted into the solid state by a separate hardening step.
These known processes for the microencapsulation of organopolysiloxanes require expensive raw materials and are technologically complicated, and thus hinder the practical use of organopolysiloxanes as shell materials in microencapsulation, although organopolysiloxanes are of considerable interest owing to their wide variation and unusual properties.